"Supernova"

What is Supernova Explosion? 💥

A supernova is an explosion of a massive supergiant star. It may shine with the brightness of 10 billion suns! The total energy output may be 1044 joules, as much as the total output of the sun during its 10 billion year lifetime.

A supernova discovered by an international group of astronomers including Carnegie's Tom Holoien and Maria Drout, and led by University of Hawaii's Ben Shappee, provides an unprecedented look at the first moments of a violent stellar explosion. The light from the explosion's first hours showed an unexpected pattern, which Carnegie's Anthony Piro analyzed to reveal that the genesis of these phenomena is even more mysterious than previously thought.

Astronomers have long tried to get detailed data at the initial moments of these explosions, with the hope of figuring out how these phenomena are triggered. This finally happened in February of this year with the discovery of a Type Ia supernova called ASASSN-18bt (also known as SN 2018oh).

ASASSN-18bt is the nearest and brightest supernova yet observed by Kepler, so it offered an excellent opportunity to test the predominant theories of supernova formation," said Shappee, who is lead author on the on the discovery and early time light curve paperand one of our Carnegie alumni.

Combining data from ASAS-SN, Kepler, and telescopes around the world, the astronomers realized that ASASSN-18bt looked unusual during its first couple of days.

"Many supernovae show a gradual increase in the light they put out," said Drout, who is jointly appointed at the University of Toronto. "But for this event, you could clearly see there's something unusual and exciting happening in the early times -- an unexpected additional emission."

The researchers were supported by a NASA Hubble Fellowship, the Villum Foundation, the U.S. National Science Foundation, the NSFC, the Research Corporation, NASA, the David G. Price Fellowship for Astronomical Instrumentation, the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions, a sabbatical grant from Aarhus University's Faculty of Science & Technology, the Gordon & Betty Moore Fation, the Heising-Simons Foundation, the Alfred P. Sloan Foundation, and the David and Lucile Packard Foundation.